The present invention relates to detection and tracking of catheters in fluoroscopic images, and more particularly, to detecting and tracking an ablation catheter and a circumferential mapping catheter in fluoroscopic images to assist in atrial fibrillation ablation treatment.
Atrial fibrillation (AF) is a rapid, highly irregular heartbeat caused by abnormalities in the electrical signals generated by the atria of the heart. It is the most common cardiac arrhythmia (abnormal heart rhythm) and involves the two upper chambers (atria) of the heart. Surgical and catheter-based therapies have become common AF treatments throughout the world. Catheter ablation modifies the electrical pathways of the heart in order to treat AF. To measure electrical signals in the heart and assist the operation, different catheters are inserted into a patient's blood vessels and guided to the heart. The entire operation is monitored and guided with real-time fluoroscopic images. The integration of static tomographic volume renderings into three-dimensional catheter tracking systems has introduced an increased need for mapping accuracy during AF procedures. However, the heart is not a static structure, and the relative motion of mapping and reference catheters can lead to significant displacements. Current technologies typically concentrate on gating catheter position to a fixed point in time within the cardiac cycle based on an electrocardiogram (ECG), without compensating for respiration effects. The often advocated static positional reference provides an intermediate accuracy in association with ECG gating.
Tracking electrodes of a circumferential mapping catheter and/or an ablation catheter in fluoroscopic images can be used for real-time guidance and to compensate respiratory and cardiac motion for 3D overlay to assist physicians when positioning the ablation catheter. However, conventional tracking algorithms encounter difficulties in the presence of large image variations, nearby similar structures, and cluttered background.